NAME

USAGE

rebingausslc infile outfile timedel timebinalg tstart tstop

DESCRIPTION

rebingausslc is a generic task which can rebin irregularly sampled light
curves. It is particularly suited to grouping irregular monitoring
observations such as Swift BAT, RXTE ASM, or long-term RXTE PCA data,
into regularly sampled time bins. It can also be used for regularly
sampled light curves, subject to the caveats below.

Users are able to choose two kinds of light curve binning: either
uniform (equal bin sizes); or custom (user chooses each bin). Each
input light curve rate sample may be a vector (eg. multiple energy
bins).

The rebinning is performed by grouping all samples that fall into an
output bin, and computing the weighted average using gaussian
statistics. This kind of statistical weighting is usually most
appropriate for background-subtracted light curves.

rebingausslc makes the following assumptions:

the input light curve has RATE-like samples;

the samples have explicit uncertainties which obey gaussian statistics(and so is not appropriate for COUNT-like light curves with low numbers of counts);

the input samples are statistically independent;

the input time bins are smaller than the output time bins;

each sample is assigned to an output bin based on the input sample's
center-time.

If the input time bins are larger than the output time bins, then this
tool is not appropriate, since the problem becomes an
interpolation problem.

rebingausslc does not compute partial exposure per bin. If at least
one sample falls in an output bin, then the bin is considered to have
full exposure. rebingausslc does not reject input bins which overlap
in time, but it also does not do anything special in such a situation
either. Once rebingausslc determins which input samples fall into a
given output bin, the samples are averaged using gaussian statistics,
assuming they are statistically independent

rebingausslc relies on the input light curve being a valid OGIP-format
light curve. This means that the appropriate TIME, RATE and ERROR
columns are present. The TIMEPIXR keyword is used to compute the
center-time of each input sample (TIMEPIXR defaults to 0.5 if not
specified). The user can specify an exposure-type column name such as
EXPOSURE so that the bin width of each input sample can be specified
explicitly.

PARAMETERS

infile [filename]

Input light curve file name.

outfile [filename]

Output light curve file name.

timedel = 1.0 [real]

Select an output time bin size, in the same units as the input "time"
column. If timebinalg="gti", then this value should be set to 0.

timebinalg = uniform [string]

Time binning algorithm. Either "uniform", for uniform binning, or
"gti" for custom time bins specified by the gtifile. Only the first
character of the algorithm type needs to be specified.

tstart = INDEF [string]

Start time of the accumulation, expressed in the same time system
as the input "time" column. This parameter is also allowed to be
"INDEF", which causes the task to use the minimum time from the file,
or "#KEYNAME" where KEYNAME is any keyword in the input file. If
timebinalg="gti", then this value should be set to INDEF.

tstop = INDEF [string]

Stop time of the accumulation, expressed in the same time system
as the input "time" column. This parameter is also allowed to be
"INDEF", which causes the task to use the minimum time from the file,
or "#KEYNAME" where KEYNAME is any keyword in the input file. If
timebinalg="gti", then this value should be set to INDEF.

(gtifile = NONE) [string]

Name of custom time bin file (if timebinalg="gti"). This file
should be a standard GTI file which contains one good time interval
per desired output bin. The GTI should have columns START and STOP,
which specify the start and stop time of each desired output bin, in
the same time units as the input light curve. If timebinalg="user"
this value should be set to NONE.

(timepixr = 0.5) [real]

Determines the reference point of each output time bin. A
value of 0.0 indicates that the output TIME column should refer to the
start of the bin; a value of 0.5 indicates the center of the bin.

(tcol = "TIME") [string]

Name of TIME column in input file.

(ratecol = "RATE") [string]

Name of RATE-like column in input file. The RATE may be a vector.

(errcol = "ERROR") [string]

Name of column in input file specifying the gaussian uncertainties
of each RATE value. The ERROR must have the same vector dimension as
RATE.

(expocol = "TIMEDEL") [string]

Name of column in input file specifying the exposure of each bin.
The task checks for a column of this name, and if not present, then
checks for a keyword of the same name.

(clobber = NO) [boolean]

If the output file already exists, then setting "clobber = yes" will cause it to be overwritten.

If history = YES, then a set of HISTORY keywords will be written to
the header of the specified HDU in the output file to record the value
of all the task parameters that were used to produce the output
file.

EXAMPLES

1. Rebin a light curve to uniform 1-day bins. This light curve
spans mission elapsed time (in seconds) from 125000000 to 150000000.
The rate and uncertainties columns are RATE and RATE_ERR respectively,
and the exposure column is EXPOSURE.